Lecture 34: Anterior Pituitary Hormones

Question 1

Anterior pituitary hormones:

Answer 1

• FSH (Follicle Stimulating Hormone)
• LH (Luitenizing Hormone)
• Growth Hormone
• TSH
• Prolactin
• ACTH

Question 2

The Somatotroph endocrine cell secretes…

Answer 2

• Growth Hormone

Question 3

The Mammotroph endocrine cell secretes…

Answer 3

• Prolactin

Question 4

Feedback regulation of APG:

Answer 4

• Hypothalamus
• Releasing Hormone
• APG
• Pituitary hormone
• Target Organ
• Hormone
• Effect

Question 5

Negative Feedback Regulation of Prolactin:

Answer 5

• Dopamine neurons in the hypothalamus
• Dopamine released at median eminence
• Prolactin secretion from anterior pituitary gland
• Prolactin (back to beginning, negative feedback system using 2 seperate neurons: 1 activation, 1 turning it back off again)
• Principal regulator is prolactin inhibiting hormone
• PIH is dopamine
• Prolactin stimulates PIH secretion to inhibit prolactin secretion

Question 6

Functions of prolactin…

Answer 6

• Stimulation of Breast development

- Stimulation of milk synthesis

Question 7

Prolactin =

Oxytocin =

Answer 7

• Milk synthesis

- Milk ejection

Question 8

Regulation of Growth Hormone Secretion:

Answer 8

• Hypothalamus:
• SS = somatostatin neurons (will switch off) & GHRH neurons
• IGF-1 (Somatrophs) act on both neurons
• GH+
• Livee

Question 9

When is most growth hormone secreted?

Answer 9

• During Sleep
• Bursts during the day
• Gender difference

Question 10

GH concentrations are higher in _____ than _____.

Answer 10

• Children

- Adults

Question 11

Growth hormone is a _____-_____ hormone.

Answer 11

• Water-soluble

- Peptide

Question 12

Growth Hormone receptor is:

Answer 12

• Dimer

- Becomes rigid once growth hormone is bound

Question 13

Effects of growth hormone:

Answer 13

• Stimulates bone growth, muscles and other tissues stimulating cell division (indirect)
• Stimulates protein synthesis (direct)
• Increases blood glucose by stimulating glucose synthesis, inhibiting cellular uptake of glucose (direct)
• Increases triglyceride breakdown and free fatty acid mobilisation in adipose tissue (direct)

Question 14

Endocrine disorders associated with growth hormone:

Answer 14

• Hyposecretion: too little
• Hypersecretion: too much secretion
• Dwarfism
• Gigantism
• Hormone Receptors:
  Hyposensitive: little (or no) response
  Hypersensitive: respond too much

Question 15

Excess GH in adulthood leads to…

Answer 15

• Thickening of bones
• Soft tissues of hands, feet and face
• (Acromegaly)

Question 16

Other hormones important for growth:

Answer 16

- Thyroid hormone:
Essential for nervous system development (cretinism) = mental retardation
Increases basal metabolic rate
- Insulin
Glucose metabolism
- Cortisol
- Testosterone / Estrogen
Essential for puberty

Question 17

Compare and contrast pituitary hormone secretion:

Answer 17

• Posterior Lobe:
  Neural input from hypothalamus stimulates AP frequency
  Action potentials stimulate release of specific stored hormones
  Released hormone travels in the blood to influence the activity of target cells
• Anterior Lobe: